Here is a review of the basic lessons from Part 1 of this article:

Simply put, OG files are incompatible with the prepress and print industry.
However, if you are like most customers you want more than a general statement. You want proof or at least evidence that OG files will not work. So based on ePUB's vast experience with OG files we have attempted to provide the core inadequacies that contribute to OG's failure in the print world. The topic is complex, the article is a bit lengthy. But ePUB is never scared of the tough issues! On with the show!

The Magnificent Seven - Problems that is!!

What, specifically, do OG applications fail at? Glad you asked! ePUB has identified seven areas where OG applications fail to support the needs of the print publishing industry. These areas are:

Each of the seven failing areas cause output problems for the print industry, and all OG applications suffer from these failings. But the problems with OG applications do not stop with these magnificent seven. In addition to these failing areas, all OG applications have additional quirks that crop up at random moments in production. These quirks are impossible to identify or predict because they are dependent on production and design variables. Therefore, this article will deal only with the seven killer areas. Just understand that these seven problems are not the only potential land mines with OG files. But when you add the Magnificent Seven problems and all the potential quirks, the result gives you a clear picture of how working with OG files is a genuine challenge.

1. Color

Since OG applications are not designed for print they work only in the Red, Green, Blue (RGB) color space. OG applications do not support CMYK (Cyan, Magenta, Yellow, Black), or Spot colors (e.g., PANTONE, Toyo). Since the print industry works exclusively with either CMYK and/or Spot inks, this lack of color support is a significant problem.

To try and use RGB files for print vendors must convert the files to CMYK. The logical question is "Why does this conversion cause the Print community problems when I can output the file to my color printer?" Simply put: a desktop color printer is designed to handle the RGB color data from OG files, while most high-end prepress workflows are not. Why? It comes down to economics and market share. Customers who use OG applications drive the desktop color printer market. Therefore, the manufacturers of desktop color printers have a stake in creating products that can seamlessly convert the RGB color data from OG files to pleasing color at output. Customers who use Professional Graphics (PG) applications drive the prepress industry. Therefore, the prepress equipment manufacturers have a stake in creating products that can accurately process data from PG files for press output.

On the economics end, since most customers in the print industry use PG software not OG software it does not make sense for the print community to develop procedures for handling OG files if they rarely receive them. Commercial print companies are in business to make a profit. They will NOT devote resources to any software application unless supporting that application will generate revenue. In the case of most OG applications, it does not make economic sense for a vendor to support OG files. So, the printing community does not - it's a matter of economics.

"But," you say, "Word and Excel are the only programs I have, and the book must be printed in color." Can these files be corrected?

Is the final job in CMYK? Then yes!!
The good news is that of the problems associated with OG files, color conversion (to CMYK only) is one of the simplest to correct. In fact, for some vendors RGB to CMYK conversion is automatically built into their workflow. Therefore, it will not add to costs. The bad news is that the conversion will almost certainly cause colors to shift. Blue colors in particular are known to shift to purple in an RGB to CMYK conversion. Because of this color inconsistency customers may not get colors that match expectations. However, as long as customers are not particular about color match, OG files can be used for CMYK printing.

Is the final job in Spot Colors? No!!!
For customers who need two or more spot colors, not CMYK, OG files are much more troublesome. Why? Well because unlike CMYK output, there is no automatic feature for converting RGB data to spot color data. Therefore, this type of change must be made manually, and as everyone knows manual changes are much more time consuming and expensive. In most cases it is easier to shoot camera copy for spot colors (and color separate by mask and opaque) than it is to use files.

RGB Black
One additional problem with OG color concerns is the default Black used in most OG applications. The RGB values of OG Blacks are typically R:0, G:0, B:0. When automatically separated to CMYK, most systems convert the default Black to 100% Cyan, 100% Magenta, and 100% Yellow. Note that nothing will image on the Black plate. This causes two problems, registration and a muddy Black. There are methods of converting RGB Black to 100% Black and some vendors have figured out how to eliminate this problem. But not all vendors can make the adjustments.

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